The present invention is directed to a process and apparatus for quenching hot coke produced in a coke plant, and for thereafter recovering and utilizing the heat released from the hot coke during the quenching thereof.
More particularly, the present invention is directed to such a process and apparatus wherein hot coke produced in a coke plant is conveyed in a container, for example a transportable car, to a position beneath a removal shaft of a quenching tower, and water is sprayed onto the hot coke to quench the coke and generate steam and quenching gases.
During the quenching of coke, particularly coke which is produced from bituminous coal, by means of spraying water onto the coke, there are generated considerable quantities of steam as well as quenching gases, for example carbon monoxide, carbon dioxide, nitrogen, nitric oxides, hydrogen, hydrogen sulfide, and other harmful gases, as well as substances in powder form. The emission and introduction directly into the exterior surrounding atmosphere of such steam, quenching gases and powder substances results in a considerable stressing of the environment, the extreme degree of which has been fully understood only recently. Additionally, the direct release of heat from the hot coke into the exterior surrounding atmosphere represents a considerable energy loss.
German DT-OS 26 53 755 discloses a system wherein a charge of hot coke produced in a coke plant is positioned beneath a removal shaft of a quenching tower, and water is sprayed onto the hot coke, thereby quenching the coke and generating steam and quenching gases which rise upwardly into the removal shaft. A flue branches off from the removal shaft, and an adjustable flap shutter is arranged at the branch of the flue and the removal shaft to theoretically cause the steam and quenching gases to flow to the flue. Within the flue the steam is condensed by means of an evaporator and an expansion turbine, and the resultant condensate is thereafter removed.
However, this prior art system has several substantial inherent disadvantages. Specifically, the charge of hot coke to be quenched is located in an entirely open area, and this inherently allows a substantial heat loss. Additionally, in accordance with this prior art system, the quenching gases are directly discharged to the environment, thereby creating a substantial stressing and pollution of the environment. Additionally, a portion of the steam and quenching gases may at least partially escape through the flap shutter into the removal shaft and thereby be directly discharged to the environment.
Furthermore, in such prior art system, it is attempted to recover heat from the steam. This system is however inherently inefficient since it is possible for the steam to at least partially bypass the heat exchanger by leaking through the flap shutter and the removal shaft.
Even further, it is extremely difficult to adapt existing quenching towers to comply with such prior art system, due to the need for constructing the additional flue which must be connected to an existing quenching tower. Such construction and connection are in many cases just simply impossible.
It has also been known to wash steam resulting from a water quenching operation by means of water sprayed onto the steam to thereby remove flue coke with the washing water. In such a known arrangement however, it has been necessary to cause the quenching steam to travel through a circuitous path of travel defined by a plurality of baffle plates in a quenching tower. In such an arrangement however, it is possible for harmful gases to gather in dead spaces and thereafter be emitted.